Search

To avoid root canal recontamination and endodontic treatment failure, endodontic sealers with antibacterial activity could be an alternative. Silver nanoparticles have antibacterial activity and this study aimed to synthesize Ag@SiOAg@SiOSilver was detected in the chemical characterization of Ag@SiOThe addition of 10 wt% Ag@SiO

This study aimed to produce poly(butylene adipate-co-terephthalate) (PBAT)/niobium containing bioactive glasses (BAGNb) composites scaffolds produced by fused deposition modeling (FDM) printing and evaluate their physicochemical and biological properties in vitro and in vivo. The composite filaments were produced by melt-extrusion with the addition of 10 wt% of BAGNb (PBAT/BAGNb). Filaments without BAGNb were produced as the control group (PBAT). The filaments were characterized and were used to produce 3D-printed scaffolds using FDM. The scaffolds' structure and surface properties were assessed. In vitro cell, proliferation, and cell mineralization analysis were performed. In vivo data was obtained in the rat femur model (n = 10), and the bone repair was assessed after 15, 30, and 60 postoperative days. The printed structures presented 69.81% porosity for the PBAT/BAGNb group and 74.54% for the PBAT group. Higher cell mineralization was observed for the PBAT/BAGNb group. The in vivo data showed that the PBAT/BAGNb presented new bone formation comparable to positive controls. The combination of PBAT and BAGNb in 3D-printed scaffolds may be an alternative to produce bioactive materials with controllable shapes and properties for bone regeneration treatments.

White spot lesions (WSL) are prevalent in patients using orthodontic appliances. The presence of ion-releasing compounds in the tooth-appliance interface may limit enamel demineralization to control WSL incidence. Thus, this study aims to evaluate the mineral formation on SiNb-containing experimental orthodontic resins and the influence of these fillers on the physicochemical and biological properties of developed materials.The SiNb particles were synthesized via the sol-gel route and characterized by their molecular structure and morphology. Photopolymerizable orthodontic resins were produced with a 75 wt% Bis-GMA/25 wt% TEGDMA and 10 wt%, 20 wt%, or 30 wt% addition of SiNb. A control group was formulated without SiNb. These resins were tested for their degree of conversion, softening in solvent, cytotoxicity in fibroblasts, flexural strength, shear bond strength (SBS), and mineral deposition.The addition of 10 wt% of SiNb did not impair the conversion of monomers, cytotoxicity, and flexural strength. All groups with SiNb addition presented similar softening in solvent. The presence of these particles did not affect the bond strength between metallic brackets and enamel, with SBS values ranging from 16.41 to 18.66 MPa. The mineral deposition was observed for all groups.The use of niobium silicate as filler particles in resins may be a strategy for the adhesion of orthodontic appliances. The 10 wt% SiNb concentration resulted in a material with suitable physicochemical and biological properties while maintaining the bond strength to tooth enamel and promoting mineral deposition.

Introdução: Este estudo tem como objetivo analisar a influência do tamanho de partículas de silicato de cálcio derivadas de sol-gel na reação de presa de cimentos endodônticos bioativos. Materiais e Métodos: Partículas de silicato de cálcio derivadas de sol-gel foram sintetizadas e peneiradas para separar as partículas em diferentes tamanhos: CS400, CS200 e CS100. Um MTA comercial (Controle) foi usado como controle. O tamanho das partículas e a área superficial específica foram avaliados por difração a laser e adsorção de nitrogênio. Os cimentos foram preparados com água como líquido para a reação. O tempo de presa foi conduzido de acordo com a ISO 6876, e a cinética de presa foi analisada por espectroscopia de infravermelho transformada de Fourier (FTIR) em diferentes pontos de tempo entre 120s a 72h. Resultados: O tamanho de partícula variou entre 9,45µm (CS400) e 31,01 (Controle). A maior área de superfície foi encontrada nas partículas do grupo CS400 (15.14g/cm2). Os menores tamanhos de partícula, a maior área de superfície específica e o menor tempo de presa foram encontrados para CS400 (p, Introduction: This study aims to analyze the influence of particles size of sol-gel derived calcium silicate particles in the setting reaction of bioactive endodontic cements. Materials and Methods: Sol-gel derived calcium silicate particles were synthesized and sieved to separate the particles in different sizes: CS400, CS200, and CS100. A commercial MTA (Control) was used as control. The particle size and the specific surface area were assessed by laser diffraction and nitrogen adsorption. The cements were prepared with water as the liquid for the reaction. The setting time was conducted according to ISO 6876, and the setting kinetics was analyzed by Fourier transformed infrared spectroscopy (FTIR) at different time points between 120s to 72h. Results: The particle size varied from 9.45µm (CS400 ) to 31.01 (Control). The higher specific surface area valuer reached 15.14g/cm2 in the CS400. The smallest particle sizes, the higher specific surface area, and the lowest setting time were found for CS400 (p < 0.05). Control presented the highest setting time (p < 0.05). The FTIR analyses showed the differences in materials structure over time, with faster hydration and crystallization for CS400. The setting kinetics was slower for Control even when compared to a sol-gel derived group with similar particle size. Conclusion: The route of synthesis and the particle size influences the setting reaction of calcium silicate-based cements. The reduction of particle size for sol-gel derived calcium silicates lead to the acceleration of the setting reaction of the produced bioactive endodontic cement.

SUMMARY This study aimed to evaluate the cementation and mechanical behavior of flared root canals restored with CAD/CAM milled glass fiber post-and-core systems. Sixty-six endodontically treated human canines with a flared root canal were divided into three different groups according to the type of post: GPF received prefabricated posts; GREL received relined glass fiber posts, and GMILLED received CAD/CAM milled glass fiber posts. Cementation was performed with self-adhesive resin cement. The samples were submitted to x-ray microcomputed tomography analysis for the analysis of voids and gaps. The roots were sectioned and submitted to the push-out bond strength test. The load-to-fracture was evaluated in post-and-core systems. GMILLED presented lower void and lower gap volumes when compared to GPF and GREL. On the load-to-fracture test, GREL presented statistically significant higher values than GMILLED. GPF values had no statistically significant difference from the two other groups. On the push-out bond strength test, GPF presented statistically significant lower values when compared to GREL and GMILLED. The most common failure pattern was between dentin and cement in all groups. CAD/CAM milled glass fiber post-and-core systems presented an enhanced adaptation of glass fiber posts to flared root canal systems. Their results were comparable to relined posts in bond strength, while load-to-fracture-results for GMILLED were lower than those for GPF.

Açaí (

Dental caries is a biofilm-mediated, diet-modulated, multifactorial and dynamic disease that affects more than 90% of adults in Western countries. The current treatment for decayed tissue is based on using materials to replace the lost enamel or dentin. More than 500 million dental restorations are placed annually worldwide, and materials used for these purposes either directly or indirectly interact with dentin and pulp tissues. The development and understanding of the effects of restorative dental materials are based on different in-vitro and in-vivo tests, which have been evolving with time. In this review, we first discuss the characteristics of the tooth and the dentin-pulp interface that are unique for materials testing. Subsequently, we discuss frequently used in-vitro tests to evaluate the biocompatibility of dental materials commonly used for restorative procedures. Finally, we present our perspective on the future directions for biological research on dental materials using tissue engineering and organs on-a-chip approaches. STATEMENT OF SIGNIFICANCE: Dental caries is still the most prevalent infectious disease globally, requiring more than 500 million restorations to be placed every year. Regrettably, the failure rates of such restorations are still high. Those rates are partially based on the fact that current platforms to test dental materials are somewhat inaccurate in reproducing critical components of the complex oral microenvironment. Thus, there is a collective effort to develop new materials while evolving the platforms to test them. In this context, the present review critically discusses in-vitro models used to evaluate the biocompatibility of restorative dental materials and brings a perspective on future directions for tissue-engineered and organs-on-a-chip platforms for testing new dental materials.

This study aimed to screen the public procurement for dental adhesives in a public health system and evaluate the variables associated with the type and cost of purchased materials. A time series was conducted with secondary data collated from the Brazilian Databank of Healthcare Prices (BDHP). All public procurements for adhesive systems registered from 2010 to 2019 were collated. The frequency of purchase was described, and a multiple linear regression model was used to assess the influence of unit price on predictor variables. Multinomial logistic regression was conducted to describe the influence of selected variables on the probability of purchase for different classes of adhesive systems. A total of 2,752 purchases were analyzed, and the total cost of these materials reached US$ 7,022,659.00 in the 10 analyzed years. The 3-step Etch & Rinse adhesives corresponded to 45.63% of the processes, with increased probability of being purchased over time. The process conducted by public universities in recent years, using the auction modality, presented lower unit prices. The year of purchase, the type of institutions, the institution's location, and the procurement modality influenced the procurement process. The performed analyses contribute to the understanding of the variables associated with the procurements for adhesive systems, providing valuable information for rationalizing public expenditure and for implementing evidence-based practices to guarantee cost-effective and clinically effective procedures for users of the Brazilian public healthcare system.

Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2073-4360/14/21/4482 Este artículo de investigación pertenece al número especial "Polymers Strategies in Dental Therapy". Objective: This study aimed to develop polymer-based barrier membranes based on poly(butylene-adipate-co-terephthalate) (PBAT) with the addition of 1,3,5-triacriloilhexahydro-1,3,5- triazine (TAT). Materials and Methods: Polymeric solutions were used to produce membranes with 5 wt% and 10 wt% of TAT by solvent casting. Membranes without the addition of TAT were used as controls. The membranes were chemically characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA); surface properties were assessed by profilometry and contact angle; the mechanical behavior was evaluated by a tensile test, and the biological properties were assessed by direct–indirect cell viability and antibacterial activity by S. mutans and S. aureus colonyforming units. Results: TAT was detected in the FTIR and TGA analyses and modified the top surface of the membranes, increasing their roughness and wetness in both concentrations compared to the control group (p < 0.05). The addition of TAT, regardless of concentration, reduced the tensile strength and increased membrane stiffness (p < 0.05). The cell viability of 5 wt% TAT and 10 wt% TAT was 86.37% and 82.36%, respectively. All tested concentrations reduced the formation of biofilm on the membranes when compared to the control. Conclusion: The addition of TAT successfully resulted in the antimicrobial ability of PBAT-based barrier membranes, while it maintained acceptable levels of cell viability in membranes with adequate handling and surface properties.

Conventional biomaterials developed for bone regeneration fail to fully recapitulate the nanoscale structural organization and complex composition of the native bone microenvironment. Therefore, despite promoting osteogenic differentiation of stem cells, they fall short of providing the structural, biochemical, and mechanical stimuli necessary to drive osteogenesis for bone regeneration and function. To address this, we have recently developed a novel strategy to engineer bone-like tissue using a biomimetic approach to achieve rapid and controlled nanoscale mineralization of a cell-laden matrix in the presence of osteopontin, a non-collagenous protein, and a supersaturated solution of calcium and phosphate medium. Here, we build on this approach to engineer bone regeneration scaffolds comprising methacrylated gelatin (GelMA) hydrogels incorporated with calcium citrate core-shell microparticles as a sustained and reliable source of calcium ions for in situ mineralization. We demonstrate successful biomineralization of GelMA hydrogels by embedded calcium carbonate-calcium citrate core-shell microparticles with the resultant mineral chemistry, structure, and organization reminiscent of that of native bone. The biomimetic mineralization was further shown to promote osteogenic differentiation of encapsulated human mesenchymal stem cells even in the absence of other exogenous osteogenic induction factors. Ultimately, by combining the superior biological response engendered by biomimetic mineralization with the intrinsic tissue engineering advantages offered by GelMA, such as biocompatibility, biodegradability, and printability, we envision that our system offers great potential for bone regeneration efforts.

Objective The aim of this study was to incorporate sol–gel-derived bioactive glass as filler into experimental adhesive resins and evaluate the influence of glass composition on the physicochemical and biological properties of the developed adhesives. Materials and methods Sol–gel particles were produced with or without the addition of niobium (BAGNb or BAG, respectively). The produced particles were incorporated (2 wt%) into experimental adhesive resins formulated with 66 wt% bisphenol A-glycidyl methacrylate and 33 wt% hydroxyethyl methacrylate. Ethyl dimethyl-4-aminobenzoate and camphorquinone were used as photoinitiator system. Two experimental groups were produced: ABAGNb and ABAG. The adhesive without particles was used as control (ACG). The materials were tested for their degree of conversion, softening in solvent, and cytotoxicity. The mineral deposition was analyzed by Raman spectroscopy. Flexural strength and immediate and 1-year microtensile bond strength were evaluated. Results No statistical difference was found in degree of conversion. ABAGNb showed reduced softening and higher mineral deposition than ACG and ABAG after 28 days. ABAG and ABAGNb resulted in higher cell viability and lower flexural strength when compared to ACG. After 1-year, ABAGNb and ABAG presented statistically significant lower μTBS values. Significance Sol–gel-derived bioactive glasses promoted increased mineral deposition and cell viability for experimental adhesives with increased phosphate content and longitudinal μTBS values for the ABAGNb group. These results suggest the potential of the studied particles to be applied as bioactive fillers for dental adhesives. Reductions in longitudinal μTBS and flexural strength, however, were observed for both glasses compositions and must be considered.

Objective The aim of this study is to produce sol-gel derived calcium silicate particles (CS) and evaluate the influence of different concentration of calcium tungstate in the physical, chemical, mechanical and biological properties of developed cements. Methods Sol-gel route were used to synthesize calcium silicate particles that were characterized with x-ray difraction, Fourier transformed infrared spectroscopy, scanning electron microscopy, laser diffraction and nitrogen absorption. Cements were formulated with the addition of different concentrations of calcium tungstate (CaWO4), resulting in four experimental groups according to the CS:CaWO4 ratio: CS100 (100:0), CS90 (90:10), CS80 (80:20), CS70 (70:30). The setting time, radiopacity, compressive strength, pH, calcium release, cell proliferation and cell differentiation were used to characterize the cements. Results CS particles were succesfully sinthesized. The addition of CaWO4 increased the radiopacity and did not influenced the setting time and the mechanical properties of cements. The pH of distilled water was increased for all groups and the CS100 and CS90 groups presented incresed calcium release. Reduced cell viability was found for CS70 while CS100 and CS90 presented higher ALP activity and % of mineralized nodules after 21 days. Significance Sol-gel derived CS particles were sucssfully developed with potential to applied for the production of bioactive ceramic cements. The addition of 10% of CaWO4 resulted in cements with adequate properties and bioactivity being an alternative for regenerative endodontic treatments.

The importance of fluoride (F) for oral health is well established in the literature. However, evidence suggests that excessive exposure to this mineral is associated with adverse effects at different life stages and may affect many biological systems, especially mineralized tissues. The purpose of this study was to investigate the effects of F exposure during pregnancy and breastfeeding on the alveolar bone of the offspring since the alveolar bone is one of the supporting components of the dental elements. For this, the progeny rats were divided into three groups: control, 10 mg F/L, and 50 mg F/L for 42 (gestational and lactation periods). Analysis of the quantification of F levels in the alveolar bone by particle-induced gamma emission; Raman spectroscopy to investigate the physicochemical aspects and mineral components; computed microtomography to evaluate the alveolar bone microstructure and analyses were performed to evaluate osteocyte density and collagen quantification using polarized light microscopy. The results showed an increase in F levels in the alveolar bone, promoted changes in the chemical components in the bone of the 50 mg F/L animals (p < 0.001), and had repercussions on the microstructure of the alveolar bone, evidenced in the 10 mg F/L and 50 mg F/L groups (p < 0.001). Furthermore, F was able to modulate the content of organic bone matrix, mainly collagen; thus, this damage possibly reduced the amount of bone tissue and consequently increased the root exposure area of the exposed groups in comparison to a control group (p < 0.001). Our findings reveal that Fcan modulate the physicochemical and microstructural dimensions and reduction of alveolar bone height, increasing the exposed root region of the offspring during the prenatal and postnatal period. These findings suggest that F can modulate alveolar bone mechanical strength and force dissipation functionality., This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. R.R.L is a researcher from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and received grant under number 312275/2021-8. Also this research was funded by PROCAD Amazônia – CAPES (23038.005350/2018–78).

OBJECTIVES This study aims to evaluate the effect of non-thermal plasma (NTP) surface treatment in two composite inorganic fillers and evaluate their impact on the chemical-mechanical properties and bond strength ability of experimental resin cements. MATERIALS AND METHODS Ytterbium fluoride (YF) and barium silicate glass (BS) were characterized and submitted to different surface treatments: non-thermal plasma (NTP); non-thermal plasma and 3-(trimethoxysilyl) propyl methacrylate silanization; and 3-(trimethoxysilyl) propyl methacrylate silanization. Untreated fillers were used as a control. The fillers were incorporated at 65wt% concentration into light-cured experimental resin cements (50wt% BisGMA; 25wt% UDMA; 25wt% TEGDMA; 1mol% CQ). The degree of conversion, the flexural strength, and the microshear bond strength (μSBS) were evaluated to characterize developed composites. RESULTS YF and BS were successfully cleaned with NTP treatment. Nor NTP neither the silanization affected the degree of conversion of resin cements. The NTP predicted an increase in YF-containing resin cements flexural strength, reducing the storage impact in these materials. NTP treatment did not affect the μSBS when applied to YF, while silanization was effective for BS-containing materials. CONCLUSION NTP treatment of inorganic particles was possible and was shown to reduce the amount of organic contamination of the particle surface. YF surface treatment with NTP can be an alternative to improve the organic/inorganic interaction in resin composites to obtain materials with better mechanical properties. CLINICAL RELEVANCE Surface cleaning with NTP may be an alternative for particle surface cleaning to enhance organic-inorganic interaction in dental composites resulting in improved mechanical strength of experimental resin cements.

Aim: This study analyzed public procurements for different endodontic materials used in the Brazilian public health system and evaluated the variables related to their cost. Methods: A time-series study was performed by screening materials for endodontic application in the public Brazilian Databank of Healthcare Prices from 2010 to 2019. Data were categorized according to material composition and clinical application. The collated variables were used in a multiple linear regression model to predict the impact of unit price in procurement processes. Results: A total of 5,973 procurement processes (1,524,693 items) were evaluated. Calcium hydroxides were found in 79% of the observations (4,669 processes). Prices drop each year by US$1.87 while MTAs and epoxy resins are increasingly purchased at higher prices (US$50.87; US$67.69, respectively). The microregion, the procurement modality, and the type of institution had no influence on unit prices in the adjusted model (p > 0.05). Conclusions: Calcium hydroxide-based materials were the cheapest and most frequently purchased endodontic materials in the public health care system. Novel formulations are being implemented into clinical practice over time and their cost may be a barrier to the broad application of materials such as MTAs, despite their effectiveness.

Background: Cyanoacrylate-based adhesives provide immediate hemostasis when applied; this is attributed to their ability to form a mechanical barrier in the surgical site, favoring the coagulation process and allowing control of bleeding. The purpose of the present study was to demonstrate the in vitro effect of cyanoacrylate-based tissue adhesive and the clinical evaluation of wound healing of freshly extracted sockets with adhesives applied on an exposed collagen membrane, for preservation of the alveolar ridge. Methods: Cytotoxicity was evaluated with sulphoradamine B assay with primary fibroblasts from gingival tissue. The in vivo analysis was carried out in 10 patients needing extraction of single-rooted teeth, who met the inclusion and exclusion criteria and signed the term of free and informed consent. Alveolar preservation was carried out with a mineralized cortical allograft bone substitute and a resorbable collagen membrane that was intentionally left exposed. On the exposed membrane, the Periacryl® 90 HV was applied as a barrier. The biocompatibility of the adhesive was assessed by the Early-Wound Healing Index (EHI) and Early Wound Healing Score (EHS), of perialveolar tissues at time intervals of 12, 30- and 60-days post-surgery. Results: Reduced cell viability was observed for Periacryl® 90 HV when compared with cells without adhesive treatments. No postoperative complications were observed after the application of Periacryl® 90 HV on perialveolar tissues. Conclusion: The use of the Periacryl® 90 HV cyanoacrylate-based tissue adhesive resulted in reduced fibroblast viability in vitro, and adequate results of wound closure in the clinical evaluation of EHI and EHS scores.

Aluminum (Al) is one of the most found elements in nature in many forms, and human exposure can be quite common. Therefore, it is important to investigate the effects of exposure to Al mainly at low doses and for a prolonged period, in order to simulate human exposure in the periodontium, an important structure for support and protection of the teeth. This investigation aimed to study the aluminum chloride (AlCl3) toxicological effects in the mineral composition and micromorphology of the alveolar bone of rats. Two groups of eight male Wistar rats were used for the experiment. AlCl3 group was exposed to AlCl3 orally at a dose of 8.3 mg/kg/day for 60 days, while the control group received only distilled water. After that, the mandibles were collected and submitted to the following analyses: Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray microtomography analysis; blood was also collected for determination of Al circulating levels. Our data showed that AlCl3 was capable of increasing Al circulating levels in blood. It was able to promote changes in the mineral content and triggers significant changes in the mineralized bone microstructure, such as number and thickness of trabeculae, being associated with alveolar bone-loss.

PURPOSE To synthesize niobium silicate particles (SiNb) and incorporate into resin-based luting agents. METHODS SiNb particles were synthesized and characterized by x-ray diffraction, FTIR spectroscopy, particle size, and specific surface area. Luting agents were formulated with 50 wt% BisGMA, 30 wt% TEGDMA and 20 wt% UDMA. BAPO was used as a photoinitiator in 1mol%. The SiNb particles were incorporated into the agents at concentrations of 50 wt% (SiNb50%) or 65% wt% (SiNb65%). Barium glass particles at the same concentrations were used as controls (SiBa50% and SiBa65%). Refractive index, degree of conversion (DC), polymerization kinetics, softening in solvent, radiopacity, film thickness, color stability, flexural strength (FS) and micro shear bond strength (µSBS) were evaluated. RESULTS SiNb particles were successfully synthesized with an adequate structure to be applied as inorganic fillers. SiNb groups had higher DC, lower %ΔKHN, greater film thickness and greater radiopacity than the SiBa groups. Color stability was greater for SiNb50% and SiNb65% after six months of storage, as demonstrated by ΔE00. ΔWID values were lower for the SiBa groups. FS results decreased over time, and lower values were found for SiNb. In µSBS, the values of SiNb65% were higher at 24 h (45.22 MPa) and at six months (36.83 MPa), with statistically differences from values for the SiBa groups. CONCLUSIONS SiNb particles were successfully synthesized using the sol-gel method, and their incorporation into luting agents at a concentration of up to 65% improved the physicomechanical characteristics and color stability of these agents.

Background Alcohol (EtOH) intake during adolescence has become an important public health issue. Although the detrimental effects of EtOH intake on the musculoskeletal system are well known, only a few studies have investigated its impact on the stomatognathic system of adolescents. This study aimed to investigate the effect of EtOH binge drinking on the alveolar bone and the long-term consequences after abstinence. Methods Adolescent female Wistar rats (35 days old) were exposed to 4 cycles of EtOH binge drinking (3 g/kg/d; 3 days On-4 days Off) or distilled water (control group). Alveolar bone micromorphology and vertical bone distance were evaluated at 1, 30, and 60 days after that last EtOH intake through X-ray computed microtomography. The mineral:matrix ratio was assessed through Raman spectroscopy. Results A decrease in both trabecular thickness and volume ratio, and an increase in trabecular separation were observed at the 1-day evaluation (immediate withdrawal). After 30 and 60 days, the alveolar bone parameters were found similar to control, except for the mineral:matrix ratio in the long-term abstinence. Conclusions EtOH binge drinking during adolescence results in alveolar bone damage that may persist in adulthood, even after abstinence.

Introduction: The combination of sol-gel derived calcium silicate particles and glycerol salicylate resins may enhance the pyhisico-chemical properties contribute to the understanding of the interaction between these materials. This study aims to evaluate the physical-chemical properties of resin-based bioactive endodontic cements with glycerol salicylate resins and calcium silicate particles. Materials and methods: Calcium silicate was produced by the sol-gel route, while the resin was produced by mixing 60wt% glycerol salicylate, 30wt% methyl salicylate and 10wt% distilled water. Calcium silicate was added in three different concentrations, 50, 40 and 25% by weight. The cement was tested for setting time, flow, radiopacity and pH. Results: The 50:50 group shows the time of 15min8s while the 75:25 shows the time of 256min13s (p, Introdução: A combinação entre partículas de silicato de cálcio e glycerol salicilato tem potencial para melhorar as propriedades físico-químicas de cimentos endodônticos bioativos. O objetivo deste estudo foi avaliar as propriedades físico-químicas de cimentos resinosos contendo glicerol salicilato e silicatos de cálcio. Materiais e métodos: O silicato de cálcio foi produzido pelo método sol-gel, enquanto o líquido foi obtido pela mistura de 60% de salicilato de glicerol, 30% de salicilato de metila e 10% de água destilada em peso. O silicato de cálcio foi adicionado em três diferentes concentrações, sendo elas 50, 40 e 25% em peso. O cimento foi testado em relação ao tempo de presa, escoamento, radiopacidade e pH. Resultados: O grupo 50:50 apresentou tempo de presa de 15min8s enquanto o 75:25 apresentou um tempo de 256min13s (p < 0,05). O grupo 50:50 apresentou menor escoamento (15,156mm) em comparação ao 60:40 (23,588mm) e 75:25 (25,396mm). Quanto à radiopacidade, todos obtiveram valores menores que 3mmAl. Todos apresentaram aumento de pH até 24h, e após esse período tiveram quedas inversamente proporcionais a quantidade de silicato de cálcio em cada um. Discussão: Partículas bioativas de silicato de cálcio foram utilizadas em um compósito com base resinosa de glicerol salicilato. Dentre os cimentos utilizados, a combinação de 50:50 entre os componentes tem resultados promissores para a aplicação destes materiais. Conclusão: O grupo 50:50 apresentou adequado tempo de presa e pH, indicando que o material pode manter suas propriedades biológicas. A radiopacidade e o escoamento, no entando, devem ser adequadas para aplicação do material.

Bone mineralization is a highly specific and dynamic nanoscale process that has been studied extensively from a structural, chemical, and biological standpoint. Bone tissue, therefore, may be defined by the interplay of its intricately mineralized matrix and the cells that regulate its biological function. However, the far majority of engineered bone model systems and bone replacement materials have been unable to replicate this key characteristic of bone tissue; that is, the ability of cells to be gradually and rapidly embedded in a three-dimensional (3D) heavily calcified matrix material. Here we review the characteristics that define the bone matrix from a nanostructural perspective. We then revisit the benefits and challenges of existing model systems and engineered bone replacement materials, and discuss recent efforts to replicate the biological, cellular, mechanical, and materials characteristics of bone tissue on the nano- to microscale. We pay particular attention to a recently proposed method developed by our group, which seeks to replicate key aspects of the entrapment of bone cells within a mineralized matrix with precisions down to the level of individual nano-crystallites, inclusive of the bone vasculature, and osteogenic differentiation process. In summary, this paper discusses existing and emerging evidence pointing towards future developments bridging the gap between the fields of biomineralization, structural biology, stem cells, and tissue engineering, which we believe will hold the key to engineer truly functional bone-like tissue in the laboratory.

We aimed to investigate the effects of chronic stress (CS) on experimental periodontitis (EP) in rats. For this, 28 Wistar rats were divided into four groups: control, ligature-induced experimental periodontitis (EP), chronic stress (CS, by physical restraint model) and CS+EP (association of chronic stress and ligature-induced periodontitis). The experimental period lasted 30 days, including exposure to CS every day and ligature was performed on the 15th experimental day. After 30 days, the animals were submitted to the behavioral test of the elevated plus maze (EPM). Next, rats were euthanized for blood and mandible collection in order to evaluate the oxidative biochemistry (by nitric oxide (NO), reduced-glutathione activity (GSH), and thiobarbituric acid reactive substance levels (TBARS)) and alveolar bone characterization (by morphometric, micro-CT, and immunohistochemistry), respectively. The behavioral parameters evaluated in EPM indicated higher anxiogenic activity in the CS and CS+EP, groups, which is a behavioral reflex of CS. The results showed that CS was able to change the blood oxidative biochemistry in CS and CS+EP groups, decrease GSH activity in the blood, and increase the NO and TBARS concentrations. Thus, CS induces oxidative blood imbalance, which can potentialize or generate morphological, structural, and metabolic damages to the alveolar bone.

Aim To develop an endodontic sealer with amoxicillin-loaded microsphere and to evaluate its properties. Methods Experimental sealer was obtained by mixing 70 wt% UDMA, 15 wt% GDMA and 15 wt% BISEMA. In addition, CQ, DHEPT and PB were incorporated at 1 mol% and 0.01 wt% BHT and 10 wt% YbF3. Microspheres were produced by drying in spray dryer. Two experimental groups (10 and 15 wt% of microspheres) and one control group (without microspheres) were formulated. The sealers were evaluated for the degree of conversion (n = 3), degradation in solvent (n = 3), drug release profile (n = 3), antimicrobial activity (n = 3), flow (n = 3), film thickness (n = 3) and cytotoxicity (n = 3). Data were analyzed by ANOVA and Tukey with significance level of 5%. Results Microespheres presented a mean size of 2.664 μm. Immediate degree of conversion ranged from 51.73% to 55.13% and the 24 h degree of conversion ranged from 60.79% to 73.80%. Upon solvent degradation 54.44% and 56.21% reduction in hardness were observed for 10% and 15% concentrations respectivelly. The drug release profile showed an average release of 73.76% of the drug in 96 h. Significant reduction in antimicrobial activity was observed for 10% concentration after 24 h, 48 h and 96 h compared to control. The flow and film thickness showed values in accordance to the ISO 6876. Cytotoxicity showed high cellular viability. Conclusion The addition of up to 10% of microspheres containing amoxicillin presented antimicrobial activity and did not alter the properties of the experimental endodontic cement. Clinical significance Amoxicillin microspheres with its antimicrobial activity in root canal sealers could reduce reintervations in endodontics when persistent bacteria or reinfection takes place in root canal system.

The aim of this study was to develop and to characterize a methacrylate-based root canal sealer containing chlorhexidine (CHX) and α-tricalcium phosphate (α-TCP). Experimental dual cure methacrylate-based sealer was produced containing 0, 2.5, or 5 wt% of CHX and 0, 25, or 50 wt% of α-TCP. Experimental sealers were evaluated based on flow, film thickness, radiopacity, degree of conversion (DC), degradation in water, pH and antibacterial activity. Flow ranged from 15.09 ± 0.11 to 17.47 ± 0.42 mm. All groups presented mean film thickness lower than 50 µm and had radiopacity equivalent to 3 mmAl. DC was higher than 60% for all compositions. The weight loss (WL) ranged 0.12-3.47%. The groups containing 5% of CHX presented the highest WL and the lower pH values after 28 days of water immersion. All chlorexidine-compositions exhibited antibacterial efficacy against Enterococcus faecalis on direct contact and agar diffusion tests. CHX and α-TCP addition at an experimental methacrylate-based root canal sealer influenced the physicochemical properties and provided antibacterial properties. The incorporation of CHX and α-TCP could be an alternative to antibacterial sealers with potential to improve periapical healing in endodontic treatments. © 2017 Wiley Periodicals, Inc. J Biomater Res Part B: 106B: 1439-1443, 2018.

Objectives This study aimed to evaluate the influence of niobium silicate (SiNb) particles in the physicomechanical and biological properties of an experimental composite resin. Methods The SiNb particles were incorporated (50 wt%) into a polymeric matrix formulated with 70 wt% Bisphenol A-Glycidyl Methacrylate and 30 wt% Triethylene Glycol Dimethacrylate to formulate an experimental composite resin. A control group was formulated with barium silicate glass (SiBa) as filler for the same polymeric matrix. The composite resins were tested for their refractive index, polymerization kinetics, flexural strength, radiopacity, softening in solvent, pH, cytotoxicity and mineral deposition. Results The SiBa group presented refractive index results between 1.50 and 1.52 and the SiNb between 1.43−1.45. No statistically significant difference in the degree of conversion, flexural strength, and softening in solvent was observed between different groups. Radiopacity was lower for SiNb, while the addition of these particles increased cell viability. The pH was increased for all groups after immersion. The mineral deposition analysis resulted in increased deposition above specimens after the immersion in SBF. Significance Niobium silicate particles may be used as an alternative inorganic filler to achieve an adequate balance between physical-chemical and biological properties for the development of bioactive composite resins.

BackgroundPeriodontitis is a multifactorial inflammatory disease of tooth supporting tissues caused by oral biofilms, influenced by environmental and genetic factors, among others. Ethanol consumption has been considered a factor that enhances alveolar bone loss, especially in high doses. The present study aims to investigate the changes promoted by ethanol binge drinking per se or associated with ligature-induced periodontal breakdown on alveolar bone loss.Materials and methodsThirty-two Wistar rats were randomly allocated into four groups: control (C), ethanol (3g/kg/day; 3 days On-4 days Off protocol by gavage for 28 days, EtOH), experimental periodontitis (EP) and experimental periodontitis plus ethanol administration (EP+EtOH). On day 14th, periodontitis was induced by ligatures that were placed around the lower first molars. On day 28th, the animals were euthanized and mandibles were submitted to stereomicroscopy for exposed root area analysis and micro-computed tomography (micro-CT) for the evaluation of alveolar bone loss and microstructural parameters.ResultsThe results revealed that ligature-induced alveolar bone loss is aggravated by ethanol binge drinking compared to controls (1.06 ± 0.10 vs 0.77 ± 0.04; pConclusionsIn conclusion, intense and episodic ethanol intake decreased alveolar bone quality in all microstructural parameters analyzed which may be considered a modifying factor of periodontitis, intensifying the already installed disease.

The aim of the present study was to formulate dental adhesives with different concentrations of LiNbO3 and to evaluate their physicochemical and antibacterial properties. A dental adhesive was formulated using methacrylate monomers and photoinitiators and used as a control filler-free group. Subsequently, three experimental adhesives doped with LiNbO3 at different concentrations (1 wt.%, 2 wt.%, and 5 wt.%) were also formulated. All the experimental adhesives were assessed to evaluate the degree of conversion (DC), softening in solvent, immediate and long-term microtensile bond-strength (&mu, TBS), radiopacity, ultimate tensile strength, and antibacterial activity. The incorporation of 1 wt.% of LiNbO3 had no negative effect on the DC of the adhesive resin compared to the control group (p &gt, 0.05). We observed a decrease in the percentage of softening in solvent in the group LiNbO3 at 1 wt.% (p &lt, 0.05). The addition of LiNbO3 increased the radiopacity at a concentration above 2 wt.%, and there was also an increase in cohesive strength (p &lt, 0.05). The immediate &mu, TBS increased for LiNbO3 at 5 wt.% (p &lt, 0.05), and there was no statistical difference for the other groups compared to the control (p &gt, 0.05). After six months, the group with 5 wt.% still presented the highest &mu, TBS (p &lt, 0.05). The adhesives showed no antimicrobial activity (p &gt, 0.05). LiNbO3 was successfully incorporated in dental adhesives, increasing the radiopacity and their resistance to degradation. Although LiNbO3 offered no antibacterial properties, the reliability of LiNbO3 incorporation in the adhesive encourages new tests to better investigate the antimicrobial action of LiNbO3 through temperature variation.

Ethanol consumption has been reported to negatively impact on periodontal disease. In particular, oral cavity disorders occur upon ethanol exposure during adolescence, a life period associated with particular patterns of short and intense ('binge-like') ethanol consumption that is most deleterious to oral health. The hazardous central effects of ethanol have been linked to the overfunction of adenosine receptors, which are antagonized by caffeine, a bioactive substance present in numerous natural nutrients, which can also modify bone metabolism. The aim of this study was to investigate the effects of caffeine on alveolar bone damage induced by an ethanol binge drinking paradigm during adolescence. Female Wistar rats (35 days old; n = 30) were allocated to six groups: control (vehicle), ethanol (3 g/kg/day; 3 days On-4 days Off challenge), caffeine (10 mg/kg/day), caffeine plus ethanol, SCH58261 (0.1 mg/kg/day, an antagonist of A2A receptors), and SCH58261 plus ethanol. Bone micromorphology and vertical bone loss were analyzed by computed microtomography. Our data showed that ethanol binge drinking reduced alveolar bone quality, with repercussion on alveolar bone size. This ethanol-induced alveolar bone deterioration was abrogated upon treatment with caffeine, but not with SCH58261. This shows that caffeine prevented the periodontal disorder caused by ethanol binge drinking during adolescence, an effect that was not mediated by adenosine A2A receptor blockade.

Este es el artículo que se ha publicado de forma definitiva en: https://www.nature.com/articles/s41598-019-44246-8 The aim of this study was to evaluate the infuence of boron-nitride nanotubes (BNNTs) on the properties of resin-based light-curing dental sealants (RBSs) when incorporated at diferent concentration. RBSs were formulated using methacrylate monomers (90 wt.% TEGDMA, 10 wt.% BisGMA). BNNTs were added to the resin blend at 0.1 wt.% and 0.2 wt.%. A Control group without fller was also designed. Degree of conversion, ultimate tensile strength, contact angle, surface free energy, surface roughness and color of the RBSs were evaluated for the tested materials. Their cytotoxicity and mineral deposition ability (Bioactivity) were also assessed. A suitable degree of conversion, no efect in mechanical properties and no cytotoxic efect was observed for the experimental materials. Moreover, the surface free energy and the surface roughness decreased with the addition of BNNTs. While the color analysis showed no diference between specimens containing BNNTs and the control group. Mineral deposition occurred in all specimens containing BNNTs after 7d. In conclusion, the incorporation of BNNTs may provide bioactivity to resin-based dental sealants and reduce their surface free energy.

This study aimed to develop bioactive guided bone regeneration (GBR) membranes by manufacturing PBAT/BAGNb composites as casting films. Composites were produced by melt-extrusion, and BAGNb was added at 10 wt%, 20 wt%, and 30 wt% concentration. Pure PBAT membranes were used as a control (0wt%BAGNb). FTIR and thermogravimetric analysis characterized the composites. Barrier membranes were produced by solvent casting, and their mechanical and surface properties were assessed by tensile strength test and contact angle analysis, respectively. The ion release and cell behavior were evaluated by pH, cell proliferation, and mineralization. Composites were successfully produced, and the chemical structure showed no interference of BAGNb in the PBAT structure. The addition of BAGNb increased the stiffness of the membranes and reduced the contact angle, increasing the roughness in one side of the membrane. Sustained pH increment was observed for BAGNb-containing membranes with increased proliferation and mineralization as the concentration of BAGNb increases. The incorporation of up to 30 wt% of BAGNb into PBAT barrier membranes was able to maintain adequate chemical-mechanical properties leading to the production of materials with tailored surface properties and bioactivity. Finally, this biomaterial class showed outstanding potential and may contribute to bone formation in GBR procedures.

Objective This study aims to analyze the addition of niobium silicate particles to dental adhesive resins and evaluate its physicomechanical and biological properties. Methods: The SiNb particles were produced by the sol-gel route and presented a mean particle size of 2.1 μm and a specific surface area of 616,96m2/g. An experimental adhesive resin was formulated with 66 wt% Bisphenol A-Glycidyl Methacrylate and 33 wt% Hydroxyethyl methacrylate with diphenyl(2,4,6-trimethyl benzoyl)phosphine oxide as the photoinitiator. The SiNb particles were incorporated into the adhesive resins in 1 wt% (SiNb1%) and 2 wt% (SiNb2%) concentration. A control group (SiNb0%) without the addition of particles was used. The developed adhesives were evaluated by their polymerization kinetics, refractive index, softening in solvent, cytotoxicity, mineral deposition, ultimate tensile strength, and micro shear bond strength. Results The refractive index range was increased by the addition of niobium silicate particles. No statistically significant difference was found between groups in the degree of conversion,.softening in solvent analysis, cytotoxicity and ultimate tensile strength. The deposition of minerals increased after immersion of specimens in SBF after 14 days on the SiNb2%. The SiNb2% group showed high micro shear bond strength values, reaching 33.87 MPa. Conclusion: In the present study, the addition of 2 wt% of niobium silicate into dental adhesive resins promoted the mineral deposition with increased bond strength without affecting other material properties. Clinical significance: Bioactive fillers must maintain the physical-chemical properties of dental adhesives, guaranteeing their clinical performance. Niobium silicate particles could promote the remineralization of dentin hard tissues without compromising the physico-mechanical properties on these materials.

Objective The aim of this study is to investigate bone healing ability of niobium-containing bioactive glasses in rat femur model with quantitative and qualitative measurements through x-ray computed microtomography. Methods Niobium-containing bioactive powders and scaffolds were produced by sol–gel route (BAGNb). Glasses without niobium addition were produced as well (BAG). Five groups were used: BAGNb powders, BAG powders, BAGNb scaffolds, BAG scaffolds and, as a control group, autogenous bone was used. Materials were implanted in the femur of male rats (Wistar Lineage n = 10) and the healing was observed after 15, 30 and 60 days. After the post-operative times, samples were scanned by X-ray microcomputed tomography where morphometric measurements and the mineral density were assessed in image software. Results No postoperative complications were observed after surgery. BAGNb glasses presented higher mineral deposition, which was observed in the relative volume of bone and the mineral density when compared BAG groups. In these parameters, no statistical difference was found between BAGNb and autogenous bone. The BAGNb powders presented a higher amount of mineralized tissue when compared to BAGNb scaffolds. The analysis of trabecular structure showed lower trabecular formation in synthetic materials when compared to autogenous bone. Significance Niobium-containing bioactive glasses promoted bone formation comparable to that of the autogenous bone without compromising the quality of the formed bone.

Orthodontic adhesives with antimicrobial and remineralizing properties may be an alternative to control white spot lesions around brackets. The aim of this study is to develop an experimental orthodontic adhesive containing boron nitride nanotubes (BNNT) and alkyl trimethyl ammonium bromide (ATAB). Methacrylate (BisGMA and TEGDMA) monomers were used to formulate the adhesives. Four experimental groups were produced with the addition of 0.1 wt.% BNNT (GBNNT), 0.1 wt.% ATAB (GATAB), and 0.2 wt.% BNNT with ATAB (GBNNT/ATAB), in the control group, no fillers were added (GCtrl). The degree of conversion, cytotoxicity, softening in solvent, contact angle and free surface energy, antibacterial activity, shear bond strength, and mineral deposition were evaluated. Adhesives achieved degree of conversion higher than 50% and cell viability higher than 90%. GBNNT and GATAB adhesives exhibited reduced softening in solvent. Mean free surface energy was decreased in the GBNNT adhesive. Significant reduction in bacterial growth was observed in the GBNNT/ATAB. No statistical difference was found for shear bond strength. Mineral deposition was found in GBNNT, GATAB, and GBNNT/ATAB groups after 14 and 28 days. The addition of 0.2% BNNT/ATAB to an experimental orthodontic adhesive inhibited bacterial growth and induced mineral deposition without affecting the properties of the material.

Objective This study aimed at evaluating the effects of experimental endodontic sealers containing halloysite nanotubes (HNT) doped with alkyl trimethyl ammonium bromide (ATAB). Methods An experimental dual-cure resin sealer was formulated and used as control material. This resin was also filled with ATAB and HNT at different ratios (GATAB:HNT 1:1; 1:2; 2:1) generate three experimental resin sealers. The ATAB:HNT filler was characterized through transmission electron microscopy (TEM). While, the experimental and control sealers were evaluated for degree of conversion, softening ration, radiopacity, flow, film thickness, antibacterial activity for biofilm and planktonic bacteria and cytotoxicity in human pulpal cells. Results GATAB:HNT (1:1) significantly increased the immediate DC (p 0.05). All the experimental cements (ATAB/HNT) showed relatively low initial Knoop hardness (p 0.05) after storage in ethanol (softening ratio). The radiopacity of all groups achieved at least 3 mm of aluminum. All groups showed more than 17 mm of flow, with a film thickness lower than 50 μm (ISO 6876:2012). All the experimental ATAB:HNT cements showed antibacterial activity against E. faecalis; the higher the ATAB ratio, the greater the antibacterial activity (p 0.05). Significance The incorporation of ATAB/HNT into the experimental resin sealers induced antibacterial activity against biofilm and planktonic E. faecalis without affecting the pulp cell viability or the chemo-mechanical properties.

Objective The aim of this study was to formulate and evaluate experimental orthodontic adhesives with different concentrations of 1-n-butyl-3-methylimidazoilium bis(trifluoromethanesulfonyl)imide (BMIM.NTf2). Methods The experimental orthodontic adhesives were formulated with methacrylate monomers, photoinitiators and silica colloidal. The ionic liquid BMIM.NTf2 was synthesized and characterized. BMIM.NTf2 was added at 5 (G5%), 10 (G10%) and 15 (G15%) wt.%. One group contained no BMIM.NTf2 to function as control (GCtrl). The adhesives were evaluated for polymerization kinetics, degree of conversion (DC), Knoop hardness and softening in solvent, ultimate tensile strength (UTS), shear bond strength (SBS), thermogravimetric analysis (TGA), antibacterial activity and cytotoxicity. Results BMI.NTf2 showed the characteristic chemical peaks. The polymerization kinetics were different among the groups. G10% and G15% showed higher DC (p 0.05). There were no differences for UTS (p > 0.05) and SBS (p > 0.05). TGA showed one different peak for G15%. All groups with BMIM.NTf2 showed antibacterial activity compared to GCtrl (p 0.05). Significance To reduce biofilm formation around brackets and to prevent demineralization at susceptible sites, materials have been developed with antibacterial properties. In this study, a new experimental orthodontic adhesive was formulated with an imidazolium ionic liquid (BMIM.NTf2) as antibacterial agent. The incorporation of 5 wt.% of ionic liquid decreased biofilm formation without affecting the physico-chemical properties and cytotoxicity of an experimental orthodontic resin.

The aim of this study was to evaluate the influence of [2-(methacryloyloxy)ethyl] trimethylammonium chloride (METAC) in the physico-chemical properties, antibacterial activity and cytotoxicity of an experimental resin–based sealant. An experimental resin-based sealant was formulated with dimethacrylates and a photoinitiator system. METAC was added at 2.5 wt.% (G2.5%) and 5 wt.% (G5%) into the experimental resin–based sealant, and one group remained without METAC as control (GCTRL). The resin-based sealants were analysed for polymerization behaviour and degree of conversion (DC), Knoop hardness (KHN) and softening in solvent (ΔKHN), ultimate tensile strength (UTS), contact angle, surface free energy (SFE), immediate and long-term micro-shear bond strength (μ-SBS) and antibacterial activity and cytotoxicity against human keratinocytes. The experimental resin–based sealants presented different polymerization behaviours without significant differences in the DC (p > 0.05). There was no significant difference for initial KHN (p > 0.05). The ΔKHN ranged from 51.62 (±3.70)% to 62.40 (±4.14)%, with higher values for G5% (p 0.05). There were no significant differences for UTS, contact angle and SFE among groups (p > 0.05). G2.5% and G5% presented immediate and long-term antibacterial activity (p 0.05). The addition of METAC provided antibacterial activity to the experimental resin–based sealant. METAC is an effective quaternary ammonium compound as an antibacterial agent for resin-based sealants without cytotoxic effects against human keratinocytes.